Si-containing thin films are used widely in the semiconductor, photovoltaic, LCD-TFT, flat panel-type device, refractory material, or aeronautic industries. Si-containing thin films may be used, for example, as dielectric materials having electrical properties which may be insulating (SiO2, SiN, SiCN, SiCOH, MSiOx, wherein x is greater than zero), Si-containing thin films may be used as conducting films, such as metal silicides or metal silicon nitrides. Due to the strict requirements imposed by downscaling of electrical device architectures towards the nanoscale (especially below 28 nm node), increasingly fine-tuned molecular precursors are required which meet the requirements of volatility (for ALD process), lower process temperatures, reactivity with various oxidants and low film contamination, in addition to high deposition rates, conformality and consistency of films produced.
Organoaminosilanes have been used as precursors for CVD of Si-containing films. U.S. Pat. No. 7,192,626 to Dussarrat et al. reports the use of trisilylamine N(SiH3)3 for deposition of SiN films. Other reported precursors include diisopropylaminosilane [SiH3(NiPr2)] and analogous SiH3(NR2) compounds (see, e.g., U.S. Pat. No. 7,875,312 to Thridandam et al.) and phenylmethylaminosilane [SiH3(NPhMe)] and related substituted silylanilines (see, e.g., EP 2392691 to Xiao et al.).
Hunks et al. disclose a wide range of Si-containing precursors in US2010/0164057, including silicon compounds having the formula R4-xSiLx, wherein x is an integer having a value from 1 to 3; R may be selected from H, branched and unbranched C1-C6 alkyl, C3-C8 cycloalkyl, and C6-C13 aryl groups; and L may be selected from isocyanato, methylethylketoxime, trifluoroacetate, triflate, acyloxy, β-diketiminate, β-di-iminate, amidinate, guanidinate, alkylamino, hydride, alkoxide, or format ligands. Pinnavaia et al. claim a method for the preparation of a porous synthetic, semi-crystalline hybrid organic-inorganic silicon oxide composition from silicon acetylacetonate and silicon 1,3-diketonate precursors (U.S. Pat. No. 6,465,387).
Penta- and hexa-coordinate sulfur containing silicon compounds are also known in the art (see, e.g., Baus et al., Neutral Six-Coordinate and Cationic Five-Coordinate Silicon (IV) Complexes with Two Bidentate Monoanionic N,S-Pyridine-2-thiolato(-) Ligands, Inorganic Chemistry (2013), 52 (18), 10664-10676; Synthesis and characterization of pyrrolidine-N-carbodiothioate and its Group IV metal complexes, Siddiqi et al., Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry (1994) 24 (3), 353-63; U.S. Pat. No. 2,590,039 to Richter et al.).
Despite the wide range of choices available for the deposition of Si containing films, additional precursors are continuously sought to provide device engineers the ability to tune manufacturing process requirements and achieve films with desirable electrical and physical properties.